Originally Posted by: Bling_Dogg01 Will it be bad if I connect with a negative instead of a positive (or vice versa)?

> come with a selection of tip sizes which you fit according to polarity
> (positive or negative centre) the instructions with the pedals should
> tell you the correct polarity,

Just my 2 cents worth... I've got several adapters like that (with the removable plugs that can be placed either negative or positive) and I'm constantly having problems with them. First of all, the wire connectors constantly become detatched from the plug because they don't fit snug enough. So the cable is constantly falling out while the plug remains in the pedal. Second problem is the negative and positive indicators are really small, black on black printing... so if it does fall out, you need a strong flashlight and a magnifying glass to put the plug back in the right way.
Third problem is the block part of the adapter is huge, heavy and doesn't come with anywhere near enough cable. So you always need to use an extension cord and you can't be more than a few feet away from the block thing because that cable is too short as well.

As far as putting it in the wrong way... after having mine fall out at least 100 times and putting it back in the wrong way on my video camera for instance, I've never had a problem with it. The camera just doesn't work if the polarity is reversed. However, many years ago I had a pedal that started smoking after I put a 9 volt battery in the wrong way, so I wouldn't recommend it.